Semi-random musings about SQL Server performance

For Day 2, lets talk about the top five reasons that will help you make the case for an upgrade and migration effort to SQL Server 2016 or SQL Server 2017.

Useful new features that are not available in legacy versions of SQL Server

Enhancements for existing features compared to legacy versions of SQL Server

New programmability features available in SQL Server 2016 Standard Edition

Higher license limits in SQL Server 2016

Support for new hardware and storage features

Useful New and Improved Features

The list of new features that might be relevant for you depends on your workload and usage scenarios. It also depends on how old the legacy version of SQL Server is compared to the version you would like to upgrade to. For example, it makes a big difference whether you are moving from SQL Server 2005 to SQL Server 2017, or whether you are just moving from SQL Server 2014 to SQL Server 2017. The bigger the gap, the more new features that are going to be available.

It also depends of what SQL Server components you will be installing and using. This series is going to primarily cover Database Engine information, but if you are going to be using other major components, such as SSRS, SSIS, or SSAS, you will have to do additional research.

Microsoft does an uneven job of listing and fully documenting/explaining all of the new and improved features in each recent version of SQL Server, as shown in the links listed below:

If you dig deeper, there are more technical blogs from Microsoft that give a lot more detail and also include additional enhancements that often are not listed in the official documentation. Here are some of the best sources of that type of information:

With the release of SQL Server 2016 Service Pack 1, many programmability features that were formerly on available in SQL Server 2016 Enterprise Edition were made available in SQL Server 2016 Standard Edition (and also in Web Edition and Express Edition). This makes it more attractive and feasible for someone to upgrade from a legacy version of SQL Server Standard Edition to SQL Server 2016 Standard Edition.

In some cases, you may also be able to go from a legacy version of SQL Server Enterprise Edition to SQL Server 2016 Standard Edition, although this may be more difficult than it seems at first due to throttling of some programmability features in Standard Edition and low SQL Server 2016 License limits for memory, sockets, and cores. Here are some links with more information about this:

SQL Server 2014 added a new feature called Buffer Pool Extension (BPE) that can be helpful in some scenarios with OLTP workloads. It is mainly interesting with SQL Server Standard Edition (due to its low memory license limit). Unfortunately, Microsoft has not chosen to invest any additional development resources in the feature in newer releases.

Microsoft did do some interesting work in SQL Server 2016 with adding support for specific processor instruction sets for some types of operations that would benefit from that support. They also added support for tail of the log caching using persistent memory (PM) in SQL Server 2016 (when running on Windows Server 2016). I mapped some of these new features to specific processor families here:

Today is the start of a new series of blog posts about upgrading and migrating to SQL Server 2016/2017 from an older version of SQL Server. It is also my birthday, so I figured it was a good time to start this series!

For Day 1, lets talk about why you might want to go through the time, trouble, and expense of upgrading and migrating to SQL Server 2016 or SQL Server 2017. First, it is pretty likely that you have multiple older versions of SQL Server, running on multiple older versions of Windows Server, running on older hardware (whether it is bare metal or virtualized), using older, slower storage (by modern standards).

Depending on how old your version of SQL Server is, it is probably out of mainstream or even extended support by now. That doesn’t mean that it suddenly stops working, but it does mean that there won’t be any more Service Packs or Cumulative Updates available.

As I discussed here, SQL Server 2012 and older are all out of mainstream support (with SQL Server 2005 and older being out of extended support). Only SQL Server 2014 and SQL Server 2016 are still fully supported by Microsoft, and they have a wealth of useful new features that are not available in previous versions.

This series is going to dive deeper into the why and how of making the case for an upgrade, and will cover useful tips for having a smooth migration process.

If you have been thinking about buying/building a new desktop development/testing machine that has enough resources to run multiple concurrent large virtual machines or a large SQL Server workload, you might want to consider an AMD Ryzen Threadripper-based machine.

AMD is doing a hard launch of this processor family on August 10, 2017. The two high-end models in the lineup (the 16-core Threadripper 1950X and the 12-core Threadripper 1920X) will be available immediately, while the lower-end Threadripper 1900X will be available on August 31, 2017.

Unlike Intel, all of these Threadripper processor SKUs are going to be able to access all of the resources of the new AMD X399 chipset-based motherboards, such as eight DDR4 memory slots, multiple M.2 slots, and 64 PCIe 3.0 lanes (although four are reserved for the chipset).

These processors are also significantly less expensive than similar core count Intel Skylake-X HEDT processors. Their single-threaded performance is probably not as good as Intel, but the gap is not that large. Figures 1 and 2 have some more details.

Besides being out of support, these old versions of SQL Server are missing many very useful new features that can benefit your organization, and make your life as a DBA much easier. In my experience, you need to take the lead, and push your organization to start upgrading, making the business and technical case to justify the effort. I have done a lot of work and research to help you with this undertaking.

In August, I will be doing a daily blog series about upgrading to SQL Server 2016/2017. Finally, I will be presenting a half-day session called Migrating to SQL Server 2017 at the PASS Summit 2017 in Seattle, WA from October 31- November 3, 2017.

CPU-Z 1.80 was released on July 10, 2017. It adds support for the new Intel Skylake-X and Kabylake-X high-end desktop processors (HEDT). It also adds information about your preferred core(s) in the Clocks dialog on the About tab.

As Kimberly blogged about earlier this year, SQLskills has an ongoing initiative to blog about basic topics, which we’re calling SQL101. We’re all blogging about things that we often see done incorrectly, technologies used the wrong way, or where there are many misunderstandings that lead to serious problems. If you want to find all of our SQLskills SQL101 blog posts, check out SQLskills.com/help/SQL101.

One seemingly simple task that I very often see being done in a less than optimal way is creating a new database in SQL Server. Whether it is done with the SQL Server Management Studio (SSMS) GUI, or with a T-SQL CREATE DATABASE command, many people and organizations are creating new SQL Server databases without really thinking about what they are doing, and without taking advantage of a number of beneficial options and properties.

A SQL Server database requires one data file in the PRIMARY file group and one transaction log file. A very high percentage of SQL Server databases that I see in the wild only have these two required files, which can be problematic for a number of reasons related to both manageability and performance.

You should get in the habit of creating a new file group called MAIN, that is the default file group, that contains two or more data files that are the same size, with the same auto growth increment. If you do this, only the system objects will be in the required data file in the PRIMARY file group, while all of your user objects will be in the other data files in the MAIN file group. This will let you locate your data files across multiple LUNs (either now or in the future), which will make them easier to manage and potentially give you better I/O performance (if those LUNs actually map to separate underlying storage).

When you create a new SQL Server database, it inherits most of its properties from the model system database (unless you explicitly override those properties with ALTER DATABASE commands). By default, SQL Server creates the files for the database in the default location that was specified when SQL Server was installed, unless someone has changed those default locations using the Server Properties: Database Settings dialog shown in Figure 1.

If you do change these database default locations, you should make 100% sure that the new locations actually exist in your file system (since SQL Server does not validate them when you change them). If you change them to a non-existent location, and later try to install a SQL Server Service Pack or Cumulative Update, the Database Engine portion of the installation will fail at the end of the setup process, which could be an unpleasant surprise!

Figure 1: Server Properties: Database Settings Dialog

Another way to change the location and properties of your database files is by explicitly specifying what you want when you create the database, or afterwards, with an ALTER DATABASE command.

If you use the SSMS GUI to create a new database as shown in Figure 2, it only requires that you enter a name for the database, and then click the OK button. Even though this will work, it is not really the best method to create a new database. Instead, you should take the time to think about what you are doing and then change a few properties and settings from their default values.

Figure 2: New Database: General Dialog with default values

The first thing you should change is the Owner of the database. You should change it from <default> to sa, to ensure that your login is not the owner of the database. Next, you should change the initial size of the files to a more appropriate, larger value. You should also change the Autogrowth increment size for the files to a more appropriate, larger value that is a fixed size in megabytes rather than a percentage-based value. Finally, you may want to change the location where your initial database files will be located. Your dialog should look something like what you see in Figure 3. After all of this, don’t click OK, because you are not done yet.

Figure 3: New Database: General Dialog with modified values

Next, you should go to the Options page, as shown in Figure 4, and think about whether you want to change any of your initial database property settings. For example, you might want to change the recovery model, the compatibility level, or possibly other settings depending on your workload or SLA requirements. The point here is to carefully consider your choices and make an explicit choice rather than just blindly accepting all of the default properties

Figure 4: New Database: Options Dialog with default values

Next, we want to go to the Filegroups page, and make some changes. You should add a MAIN file group, and make it the default file group, as you see in Figure 5.

Figure 5: New Database: Filegroups Dialog with modified values

The next step is to go back to the General page and add some data files to this new MAIN file group. In Figure 6, I have added two new data files to the MAIN file group, setting their properties to appropriate values. If desired, I could change their locations in the file system. After all of this work, do not click on the OK button! Instead, use the Script dropdown to select “Script Action to New Query Window”, so you can review, edit, and save your database creation T-SQL script.

Figure 6: New Database: General Dialog with final values

As appropriate for a SQL101-level post, this covers the basic options you should consider when creating a database, as opposed to just typing a database name and clicking OK. If you take the time to do this when you first create the database, you will have a lot more flexibility in the future as your database gets larger.

This month, there are more minor updates to the all of the versions of the queries. I usually make additional minor updates to the queries during the month, so if you are in doubt, downloading the latest version is always a good idea.

Rather than having a separate blog post for each version, I have just put the links for all seven major versions in this single post. There are two separate links for each version. The first one on the top left is the actual diagnostic query script, and the one below on the right is the matching blank results spreadsheet, with labeled tabs that correspond to each query in the set.

Here are links to the latest versions of these queries for SQL Server 2017, 2016, 2014 and 2012:

Here are links to the most recent versions of these scripts for SQL Server 2008 R2 and older:

Since SQL Server 2008 R2 and older are out of Mainstream support from Microsoft (and because fewer of my customers are using these old versions of SQL Server), I am not going to be updating the scripts for these older versions of SQL Server every single month going forward. I started this policy a while ago, and so far, I have not heard any complaints. I did update these queries slightly in January 2017 though.

The basic instructions for using these queries is that you should run each query in the set, one at a time (after reading the directions for that query). It is not really a good idea to simply run the entire batch in one shot, especially the first time you run these queries on a particular server, since some of these queries can take some time to run, depending on your workload and hardware. I also think it is very helpful to run each query, look at the results (and my comments on how to interpret the results) and think about the emerging picture of what is happening on your server as you go through the complete set. I have quite a few comments and links in the script on how to interpret the results after each query.

After running each query, you need to click on the top left square of the results grid in SQL Server Management Studio (SSMS) to select all of the results, and then right-click and select “Copy with Headers” to copy all of the results, including the column headers to the Windows clipboard. Then you paste the results into the matching tab in the blank results spreadsheet.

About half of the queries are instance specific and about half are database specific, so you will want to make sure you are connected to a database that you are concerned about instead of the master system database. Running the database-specific queries while being connected to the master database is a very common mistake that I see people making when they run these queries.

Note: These queries are stored on Dropbox. I occasionally get reports that the links to the queries and blank results spreadsheets do not work, which is most likely because Dropbox is blocked wherever people are trying to connect. I am not planning on moving these to Github any time soon.

I also occasionally get reports that some of the queries simply don’t work. This usually turns out to be an issue where people have some of their user databases in 80 compatibility mode, which breaks many DMV queries, or that someone is running an incorrect version of the script for their version of SQL Server.

It is very important that you are running the correct version of the script that matches the major version of SQL Server that you are running. There is an initial query in each script that tries to confirm that you are using the correct version of the script for your version of SQL Server. If you are not using the correct version of these queries for your version of SQL Server, some of the queries are not going to work correctly.

As Kimberly blogged about earlier this year, SQLskills has an ongoing initiative to blog about basic topics, which we’re calling SQL101. We’re all blogging about things that we often see done incorrectly, technologies used the wrong way, or where there are many misunderstandings that lead to serious problems. If you want to find all of our SQLskills SQL101 blog posts, check out SQLskills.com/help/SQL101.

On June 20, 2017, AMD officially unveiled its new EPYC 7000 Series processor line for one and two-socket servers. These 14nm processors are based on the same Zen architecture as the recent AMD Ryzen desktop processors, with competitive single-threaded performance, along with very high core counts, memory density, and PCIe 3.0 lane counts.

These processors are a system on a chip (SoC) that includes CPU, memory controller, I/O controller and Server Controller Hub, so that no separate chipset is required. They have up to 32 physical cores per SoC, along with Simultaneous Multithreading (SMT), so you get 64 logical cores per SoC. You also get eight memory channels per socket, which means 16 DDR4 DIMMs per socket. This lets you have up to 2TB of RAM in a one-socket server, and 4TB of RAM in a two-socket server (with 128GB DIMMs). More realistically, you can easily and affordably have 512GB of RAM in a single-socket server with 32GB DIMMs.

You also get 128 PCIe 3.0 lanes per socket, which gives you a lot of total I/O capability. One very nice feature of these processors is that AMD does not cripple the lower-end SKUs when it comes to SMT, memory channels or PCIe 3.0 lanes, which is a big, welcome difference from how Intel does things with their product differentiation.

Another difference from Intel (which I actually don’t like) is that AMD does not have higher base clock speeds in their lower core count SKUs, so the existing strategy to reduce your SQL Server core license costs and also get better single-threaded performance by picking “frequency-optimized” low core count (LCC) processors, such as the Intel Xeon E5-2667 v4 is not going to work the same way.

What you can and should do, is to pick the fastest AMD EPYC SKU available at a given physical core count. For example, there are three EPYC 7000 SKUs that have 32 physical cores, the EPYC 7501, the EPYC 7551, and the EPYC 7601. Since the SQL Server core license cost will be the same, you should pick the EPYC 7601, to get the most performance possible for your license dollars.

Another important caveat is for SQL Server Standard Edition users. SQL Server 2016 Standard Edition has a license limit of four sockets or 24 physical cores, whichever is lower. This means that you need to be very careful what processor you choose for SQL Server 2016 Standard Edition. You basically have five choices to avoid exceeding these license limits.

You can get a 24-core EPYC 7401P, or a 16-core EPYC 7351P for a single-socket server. The 32-core EPYC 7551P would exceed your Standard Edition license limit. In a two-socket server, you can choose an eight-core EPYC 7251, and populate either one or two sockets. You can also choose a 16-core EPYC 7351 or a 24-core EPYC 7451 and just populate one socket of a two-socket server.

If you buy a new database server that has more than 24 physical cores, SQL Server 2016 Standard Edition will only use 24 physical cores per instance, but Microsoft will still expect you to pay for a core license for every physical core present in the machine. This could be a very expensive mistake. In a worst case scenario, you buy a two-socket server with two of the 32-core EPYC 7601 processor, and end up having to pay about $72K in extra license costs for cores that you are not allowed to use in a single instance.

Microsoft has not formally announced any change in these license limits for SQL Server 2017 Standard Edition, but hopefully they will raise these license limits to a more realistic value for modern processors from AMD (and for the upcoming Intel Skylake-SP processors).

This month, there are some minor updates to the all of the versions of the queries. I usually make additional minor updates to the queries during the month, so if you are in doubt, downloading the latest version is always a good idea.

Rather than having a separate blog post for each version, I have just put the links for all seven major versions in this single post. There are two separate links for each version. The first one on the top left is the actual diagnostic query script, and the one below on the right is the matching blank results spreadsheet, with labeled tabs that correspond to each query in the set.

Here are links to the latest versions of these queries for SQL Server 2017, 2016, 2014 and 2012:

Here are links to the most recent versions of these scripts for SQL Server 2008 R2 and older:

Since SQL Server 2008 R2 and older are out of Mainstream support from Microsoft (and because fewer of my customers are using these old versions of SQL Server), I am not going to be updating the scripts for these older versions of SQL Server every single month going forward. I started this policy a while ago, and so far, I have not heard any complaints. I did update these queries slightly in January 2017 though.

The basic instructions for using these queries is that you should run each query in the set, one at a time (after reading the directions for that query). It is not really a good idea to simply run the entire batch in one shot, especially the first time you run these queries on a particular server, since some of these queries can take some time to run, depending on your workload and hardware. I also think it is very helpful to run each query, look at the results (and my comments on how to interpret the results) and think about the emerging picture of what is happening on your server as you go through the complete set. I have quite a few comments and links in the script on how to interpret the results after each query.

After running each query, you need to click on the top left square of the results grid in SQL Server Management Studio (SSMS) to select all of the results, and then right-click and select “Copy with Headers” to copy all of the results, including the column headers to the Windows clipboard. Then you paste the results into the matching tab in the blank results spreadsheet.

About half of the queries are instance specific and about half are database specific, so you will want to make sure you are connected to a database that you are concerned about instead of the master system database. Running the database-specific queries while being connected to the master database is a very common mistake that I see people making when they run these queries.

Note: These queries are stored on Dropbox. I occasionally get reports that the links to the queries and blank results spreadsheets do not work, which is most likely because Dropbox is blocked wherever people are trying to connect. I am not planning on moving these to Github any time soon.

I also occasionally get reports that some of the queries simply don’t work. This usually turns out to be an issue where people have some of their user databases in 80 compatibility mode, which breaks many DMV queries, or that someone is running an incorrect version of the script for their version of SQL Server.

It is very important that you are running the correct version of the script that matches the major version of SQL Server that you are running. There is an initial query in each script that tries to confirm that you are using the correct version of the script for your version of SQL Server. If you are not using the correct version of these queries for your version of SQL Server, some of the queries are not going to work correctly.

Over the past couple of months, SQLskills has embarked on a new initiative to blog about basic topics, which we’re calling SQL101. We’ll all be blogging about things that we often see done incorrectly, technologies used the wrong way, or where there are many misunderstandings that lead to serious problems. If you want to find all of our SQLskills SQL101 blog posts, check out SQLskills.com/help/SQL101.

Back in the SQL Server 2012 release time-frame, Microsoft published a SQL Server Core Factor Table document that essentially provided a 25% discount for most AMD Opteron processors with six or more physical cores. This document was updated for the SQL Server 2014 release.

Even with this discount, it was not really cost-effective to use AMD Opteron processors for SQL Server usage, because of their extremely poor single-threaded performance. You could easily get more total capacity, better single-threaded performance, and lower SQL Server licensing costs with an appropriate, modern Intel Xeon E5 or E7 processor.

For the SQL Server 2016 release, there was no update for the SQL Server Core Factor Table. In fact, Microsoft has a useful new document, entitled “Introduction to Per Core Licensing and Basic Definitions” where they explicitly state that the Core Factor Table is not applicable to SQL Server starting with SQL Server 2016. So far, there has been no word of any change in this stance for SQL Server 2017.

Despite this, there is still some confusion and misinformation about the SQL Server Core Factor Table, such as this example:

The SQL Server Core Factor Table is not necessary for SQL Server 2008 R2 (which used processor licensing instead of core licensing), and it does not apply to SQL Server 2016 and newer. It is only valid for SQL Server 2012 and SQL Server 2014.

It will be interesting to see whether the upcomingAMD Epyc “Naples” server processors will perform well with SQL Server workloads. They certainly will have enough memory density and PCIe 3.0 lanes to be very interesting for some types of SQL Server workloads, such as DW/Reporting. AMD is also pitching the idea that a single-socket server using an AMD Epyc processor will be a good alternative to a two-socket Intel server.